This invention relates to rotary web processing apparatus and particularly to a rotary die cutter apparatus for die cutting, perforating, embossing and otherwise surface shaping and working of a web material.
In the production of paper and film products, a continuous web of material is passed through in-line apparatus to shape, cut and otherwise operate on the material to form a product. In the processing, a rotary die cutter apparatus may be used for proper die cutting, perforating and creasing of the web material. The die cutter apparatus may consist of a smooth, hard finished anvil roll or cylinder and an opposed die cut roll or cylinder having a cutting, perforating, creasing or other working plate or member on the surface. The surface speed of the rolls and of the web material are matched to permit continuous on-line processing of the web as it moves through the rolls. In such systems, the axis parallelism and a constant gap or spacing between the rolls must be accurately set and maintained in order to maintain the proper relationship between the working members and the anvil roll for accurate and repeatable formation of the same cut or groove on the web.
Further, in high speed web processing apparatus using opposed working cylinders, great care must be taken to avoid cylinder bounce during working of the web material. Thus, the cylinders are generally gear driven at high speed. With a gap between the cylinder, there is a tendency for the cylinders to move with a slight bounce. Any such "bounce" movement of course provides an undesirable variation in the gap, and may damage the equipment and/or the work.
In many applications, die cutting apparatus uses relatively small diameter cylinders, such as ten inches in diameter. The supporting bearing structures for such rollers generally provide for various forms of gap adjusting mechanisms. Further, with relatively high speed and small diameter cylinders, relatively fine adjustment of the positioning or setting of the gap is often necessary or desired.
The prior art encountered in the prosecution of the application entitled "Adjustable Mounting For Cooperating Die Cylinders" which was filed on Sept. 29, 1980, discloses various prior art approaches to cylinder roll adjustment. For example, U.S. Pat. No. 1,289,084 discloses an adjustable lock nut arrangement for spreading the radial bearings of the unit and thereby adjusting the positioning of the cylinders. U.S. Pat. No. 4,130,042 discloses a special bearing structure including a resilient deflectable inner annular member mounted as an eccentric and a pivot arm for turning the members and pressure loading of the cylinder bearings to vary the gap.
Not withstanding the many different suggestions which have been made in the prior art, there is a need for a simple, reliable and practical construction of a gap adjustment means which can be located within the limited space available with small diameter cylinders and which includes means permitting fine adjustment by the operator, and preferably without the necessity of any particular actuation tools.
The operator or maintenance personnel can then adjust the gap with only the use of suitable gap measuring instruments to any desired requirement. The setting of course not only is dependent upon the accuracy of this setting and the tolerances within the adjusting apparatus, but also upon the technical skill and ability of the personnel making the adjustment.